THE RALEIGH TWENTY

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and other classic small-wheel bicycles.

Dawes Kingpin. Mega-modded!

Stem extender

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Stem extender
The stem extender has been fabricated from some 1 1/8" Reynolds 531 steel tube. Inside the fork is an Aheadset quill adaptor with an internal quill wedge. Inside the extender tube is a 25.4-27.2mm shim so that the extender tube fits to the quill adaptor perfectly. The lower clamp fixes the extender to the top of the fork. The upper clamp secures it to the top of the quill adapter. This 'belt and braces' method is the stiffest and strongest way to mount an Ahead stem to a Dawes Kingpin. The carbon spacers are cosmetic, and serve no structural purpose. The headset is a standard threaded Shimano 105 item, but the top nut has been reduced in height by 4mm. I also shortened the head tube by 6mm, thus allowing the lower clamp to align with the fork steerer's clamping slot. Safety first!
Posted by davepalk on April 9, 2013 Full Size|

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5 Comments

Reply davepalk
5:46 PM on August 10, 2017 
Graham Bowers says...

Hi, this is Graham Bowers
Your work with this KP is inspiring. I'm just about to start with a donated folder KP frame and build it up to be a fitted-for-me, practical and modernised (more gears, brakes that work for example) daily ride, with possible light touring (10 Kg luggage). I'm a seated spinner rather than standing pedaler by the way. Bearing in mind what you've done already, and future aspirations for modding KP's, I was surprised to read the first sentence below that advises against using a KP as a base. What has happened to cause a change of mind please? I like the KP as a base due to the standard BB threads, proper (ball bearings top and bottom) headset and, in my opinion, more elegant lines than an R20.
[/Graham Bowers]

Graham, seriously, if you want a bike that performs well, don't bother with a Kingpin. There are some advantages to the KP in terms of frame build quality and the standard threads, but a Twenty will ride much, much better. Sell the donated KP and use the money to buy a Twenty instead. Kingpins are okay (just) for use as originally intended - as ladies' shopping bikes. If you expect anything more than that, get yourself a Twenty. That extra 6 mm of main tube diameter really does make all the difference. After I built the KP it was ridden three or four times and then broken up and quickly sold off, to be replaced by a Twenty. I now have five high-performance converted Twenties, which I use for all my commuting and club cycling. They all ride perfectly and I have never looked back...
Reply Graham Bowers
3:27 AM on August 9, 2017 
Dave Palk says...
Hello Both,
Firstly, please seriously reconsider modding a Kingpin. The small diameter main tube is way too flexy for anything other than sedate, seated pedaling. You'd be better starting with a Twenty, which is far stiffer and will ride well! If you must mod a Kingpin you should braze in a top tube to triangulate the frame. If you want the stem conversion, simply cut the seat tube out of any old steel road frame. Cut a compression-clamping slot, slip the tube over a quill adapter and the top of the fork, and secure with two 28.6 mm seat clamps, as I did above. You'll need an internal shim to adapt the outside diameter of the quill adapter (and fork) to the internal diameter of the scrap frame tubing. 27.2 mm - 25.4 mm adapter shims for seatposts are readily available. I added some thin copper sheet to get a really snug fit. This conversion is highly "safety critical", so make sure everything is sound and don't take any chances. Sorry, I don't have the time to take on any fabrication work. I'm far too busy with numerous bike projects of my own! .

Thanks
James

[/Dave Palk]
Hi, this is Graham Bowers
Your work with this KP is inspiring. I'm just about to start with a donated folder KP frame and build it up to be a fitted-for-me, practical and modernised (more gears, brakes that work for example) daily ride, with possible light touring (10 Kg luggage). I'm a seated spinner rather than standing pedaler by the way. Bearing in mind what you've done already, and future aspirations for modding KP's, I was surprised to read the first sentence below that advises against using a KP as a base. What has happened to cause a change of mind please? I like the KP as a base due to the standard BB threads, proper (ball bearings top and bottom) headset and, in my opinion, more elegant lines than an R20.
Reply Dave Palk
6:28 PM on September 23, 2015 
Hello Both,
Firstly, please seriously reconsider modding a Kingpin. The small diameter main tube is way too flexy for anything other than sedate, seated pedaling. You'd be better starting with a Twenty, which is far stiffer and will ride well! If you must mod a Kingpin you should braze in a top tube to triangulate the frame. If you want the stem conversion, simply cut the seat tube out of any old steel road frame. Cut a compression-clamping slot, slip the tube over a quill adapter and the top of the fork, and secure with two 28.6 mm seat clamps, as I did above. You'll need an internal shim to adapt the outside diameter of the quill adapter (and fork) to the internal diameter of the scrap frame tubing. 27.2 mm - 25.4 mm adapter shims for seatposts are readily available. I added some thin copper sheet to get a really snug fit. This conversion is highly "safety critical", so make sure everything is sound and don't take any chances. Sorry, I don't have the time to take on any fabrication work. I'm far too busy with numerous bike projects of my own! .

Thanks
James
[/james]
Reply james
5:26 PM on September 23, 2015 
Hi
I am modding a Kingpin at the mo. Would you be able to fabricate a 531 headtube extender for me in exchange for $?

Thanks
James
Reply wesser
4:07 PM on October 20, 2013 
Hi, i have a few kingpins that will be modified in the near future. I like the idea of being able to use an ahead stem as you have done.From your description above i understand that you have fitted an ahead quill adaptor into the original fork and secured it with the expanding wedge and a clamp. How is the 531tube fitted to the top of the ahead adapter? does it fit over it? or into it?. What size is the upper part of the adaptor? I like your end result but am a little unsure of the method of fixing. please help thanks